A biomarker is a molecule that can be measured in a biological sample in an objective, systematic, and precise way, whose levels indicate whether a process is normal or pathological. Knowing the most important biomarkers and their characteristics is the key to precision medicine in intensive and perioperative care. Biomarkers can be used to diagnose, in assessment of disease severity, to stratify risk, to predict and guide clinical decisions, and to guide treatments and response to them. In this review, we will analyze what characteristics a biomarker should have and how to ensure its usefulness, and we will review the biomarkers that in our opinion can make their knowledge more useful to the reader in their clinical practice, with a future perspective. These biomarkers, in our opinion, are lactate, C-Reactive Protein, Troponins T and I, Brain Natriuretic Peptides, Procalcitonin, MR-ProAdrenomedullin and BioAdrenomedullin, Neutrophil/lymphocyte ratio and lymphopenia, Proenkephalin, NefroCheck, Neutrophil gelatinase-associated lipocalin (NGAL), Interleukin 6, Urokinase-type soluble plasminogen activator receptor (suPAR), Presepsin, Pancreatic Stone Protein (PSP), and Dipeptidyl peptidase 3 (DPP3). Finally, we propose an approach to the perioperative evaluation of high-risk patients and critically ill patients in the Intensive Care Unit (ICU) based on biomarkers.

Major noncardiac surgery is associated with a 5% incidence of serious cardiovascular complications and with a 1 to 2% probability of death from cardiac causes. Over the last few decades, researchers have assessed the perioperative predictive power of several risk indices. Research is currently focused on the evaluation of biomarkers. The objective was to determine the incidence of high serum levels of N terminal B-type natriuretic propeptide (NT-proBNP) before and after surgery in adults undergoing elective major noncardiac procedures and to evaluate its relationship with mortality and cardiovascular complications occurring up to 30 days after surgery. Prospective cohort study. Enrolment was undertaken at a university hospital from October 2011 to July 2013. A total of 304 adults with cardiovascular risk factors who underwent noncardiac elective surgery. The relationship between preoperative and postoperative NT-proBNP serum levels and the emergence of cardiovascular complications, including all-cause mortality, during the first 30 days after surgery. The incidence of cardiovascular complications was 7.8% (n = 25), and the mortality rate was 4.3% (n = 13). Higher-than-normal NT-proBNP serum levels were found before surgery in 48.4% (n = 147) and after surgery in 50.7% (n = 154) of patients. The variables found to be independent predictors of cardiovascular complications, including all-cause 30-day mortality, were levels of NT-proBNP more than 300 pg ml before surgery and levels more than 1000 pg ml both before and after surgery. High levels of preoperative and postoperative NT-proBNP are predictors of cardiovascular complications, including all-cause mortality, during the first 30 days after noncardiac surgery in adults with cardiovascular risk factors.

Background. In the hospital of La Princesa, the "Sepsis Code" (CSP) began in 2015, as a multidisciplinary group that provides health personnel with clinical, analytical and organizational tools, with the aim of the detection and early treatment of patients with sepsis. The objective of this study is to evaluate the impact of CSP implantation on mortality and to determine the variables associated with an increase in it. Material and methods. A retrospective analytical study of patients with CSP alert activation from 2015 to 2018 was conducted. Clinical-epidemiological variables, analytical parameters, and severity factors such as admission to critical care units (UCC) and the need for amines were collected. Statistical significance was established at p < 0.05. Results. We included 1,121 patients. The length of stay was 16 days and 32% required admission to UCC. Mortality showed a statistically significant linear downward trend from 24% in 2015 to 15% in 2018. The predictive mortality variables with statistically significant association were lactate > 2 mmol/L, creatinine > 1.6 mg/dL and the need for amines. Conclusions. The implementation of Sepsis Code decreases the mortality of patients with sepsis and septic shock. The presence of a lactate > 2 mmol/L, creatinine > 1.6 mg/dL and/or the need to administer amines in the first 24 hours, are associated with an increase in mortality in the patient with sepsis.

The main objective of the study was to verify whether levels of procalcitonin (PCT) could guide us toward determining the type of bacteria causing the sepsis and to identify the discriminatory cut-off point in the first urgent laboratory test. This study is a single center retrospective analysis that includes 371 patients with a mean age of 71.7 ± 15.6 years who were diagnosed with sepsis or septic shock. The yield of blood cultures in demonstrating the causative microbiological agent was 24.3% (90), and it was 57, 1% (212) when evaluating all types of cultures. Statistically significant positive differences were observed in the mean value of the PCT between the group that obtained positive cultures and the group that did not (p < 0.0001). The AUC-ROC of PCT values as a guide to the causal bacteria type was 0.68 (95%CI: 0.57–0.78, p < 0.0021). The PCT value that showed the best diagnostic characteristics for identifying Gram-negative rods (GNR) as the causative agent in blood cultures was 2.1 ng/mL. The positive predictive value (PPV) was 78, 9% (66.3–88.1%). The AUC-ROC of the PCT values for sepsis diagnosis, with any positive culture that could be assessed, was 0.67 (95%CI: 0.63–0.73, p < 0.0001). The PCT value that showed the best diagnostic characteristic for predicting sepsis was 3.6 ng/mL.

The need for postoperative organic support is associated with patient outcomes. Biomarkers may be useful for detecting patients at risk. MR-ProADM is a novel biomarker with an interesting profile that can be used in this context. The main objective of this study was to verify whether there was an association between the preoperative serum levels of MR-ProADM and the need for organic support after elective abdominal cancer surgery, and to determine the preoperative MR-ProADM value that predicts the need for postoperative organic support. This was a multicenter prospective observational study conducted by four tertiary hospitals in Spain between 2017 and 2018. Plasma samples were collected for the quantification of MR-ProADM from adults who underwent major abdominal surgery during 2017–2018. The primary outcome was the need for organic support in the first seven postoperative days and its association with the preoperative levels of MR-ProADM, and the secondary outcome was the preoperative levels of MR-ProADM in the study population. This study included 370 patients with a mean age of 67.4 ± 12.9 years. Seventeen percent (63 patients) required some postoperative organic support measures in the first week. The mean preoperative value of MR-ProADM in patients who required organic support was 1.16 ± 1.15 nmol/L. The AUC-ROC of the preoperative MR-ProADM values associated with the need for organic support was 0.67 (95% CI: 0.59–0.75). The preoperative MR-ProADM value, which showed the best compromise in sensitivity and specificity for predicting the need for organic support, was 0.70 nmol/L. The negative predictive value was 91%. A multivariate analysis confirmed that a preoperative level of MR-ProADM ≥ 0.70 nmol/L is an independent factor associated with risk of postoperative organic support (OR 2, 6). Elevated preoperative MR-ProADM levels are associated with the need for postoperative organic support. Therefore, MR-ProADM may be a useful biomarker for perioperative risk assessment.